Sony FX3 VS Sony A7S III 10 Reasons to Choose FX3

Today I’m comparing two incredibly popular Sony cameras Sony FX3 VS Sony A7S III and why you should switch from the A7S III to the FX3.

If you are currently in the market for a new camera that is more video Centric you definitely can join FX3, so, one reason to switch from A7S III and get an FX3 is because of the Lut display build into the FX3.

So, because the Sony FX3 is released should you buying an A7S III over FX3 i’m going to talk about the main differences between these two cameras and why i think it doesn’t make much sense to buy FX3.

Sony decides to update the firmware on the FX3 and with the new firmware update of the FX3 they’ve included a bunch of Sony FX6 and Sony FX9 features such as cine EI flexible ISO.

This review is about all the differences and the pros and cons of each camera to help you decide on which camera you may want to pick up and what works for your needs.

What Are the Similarities Between Sony FX3 vs Sony A7S III?

the Sony FX3 has all the amazing features of the Sony A7S III such as being a full frame 12.1 megapixel sensor, 4k 120, 240 recordings, cf express type A, and SD, and both are full-frame cameras with the same exact sensor.

the FX3 is very similar to the a7s3 it has a top handle that is removable which gives you all sorts of professional audio functions including two xlr inputs. the FX3 has the ports like full size HDMI, the same sort of input outputs that you’d find like on the A7S III including USB-C.

Both cameras can take 12-megapixel, both have the same dynamic range, same autofocus, same 5-axis in-body image stabilization including active mode, and both shoot in10-bit 4:2:2 video in all codecs.

Also can output 16-bit raw video via HDMI same touch menu screen, the same dual media card slots, and the same ports.

What Are The Differences Between FX3 and A7S III?

In terms of the differences, the A7S III features the electronic viewfinder the only thing that the FX3 does not have, there’s not mode dial, the FX3 has a design similar to the Sony A7C built-in cage around it.

I think it looks like that but of the Sony Cinema line like the Sony FX9 or Sony FX6, whereas the A7S III you have to get a cage that requires the entire setup if you want to attach those cinema accessories.

But with FX3 with the cage built around it you don’t have to buy a separate cage you can attach your accessories onto the FX3 like a handle a monitor, external microds a matte box.

the difference between the Sony A7S III and the FX3 there is one main difference its the EVF so the EVF is really important if you are a photographer when you are shooting you need to put the eye socket right up to the EVF and make sure that its good quality photo.


Sony A7S III

So, physically they’re similar in size but the A7S III features an excellent EVF whereas the FX3 only has its rear LCD for monitoring. The FX3 looks smaller than the A7S III obviously there’s that EVF on top of the camera whereas there is no EVF it only has its rear LCD for monitoring which makes the camera shorter than the A7S III.

FX3 has an internal cooling fan and heat sink to remove the heat from the actual camera you can feel a little bit of a difference in the actual handle when you hold it and it feels really good in the hand.

the A7S III also feels really nice in the hand but with this extra thickness and just a little bit extra wideness on the body you can see if you look at them straight down the actual grip is longer on the FX3.

Sony FX3

The body of FX3 is very similar to the A7C but it is a little chunkier because it has to fit something in there called a fan it doesn’t have an EVF on top, it has a power switch that goes on and off.

FX3 comes with a top handle to screw into the top and that allows you to have two xlr inputs as well as a 3.5millimeter mic input and a bunch of other different things

The FX3 is designed for the solo filmmakers it has the S-Cinetone picture profile very similar to the Sony Venice it also has a bunch of quarter-inch threads across its body for easy mounting and rigging, both cameras have different button layout and design the FX3 also has better tally lights and options than the A7S III.

the FX3 also features a fan internally which allows you to record without worrying about any overheating issues which you may realize with the A7S III.


Sony FX3 body

the screen is the exact same screen it flips out the same way front facing screen another nice perk of this handle other than just xlrs is the fact that it now makes getting low shots even easier because when you flip this out just like any camera has a handle when you are down low shooting shots this obviously is much more comfortable.

Sony A7S III

A7S III features a three inch 1.44 million dots vary angle LCD touch screen it uses the new menu system same found in the the Sony A1 and the same in the FX3. It has 5 axis ibis it has dual card slots just like in the Sony A1 that means that you can do CFexpress type A as well as SD.

The difference between those cameras is you use the CFexpress type A cards with A7S III which are really expensive, USB-C charging, full-sized HDMI, whereas Sony A1 uses only one card.

the screen of the FX3 has slightly more dots than A7S III but those are the main differences software menu system everything else was largely the same between the FX3 and the A7S III.

Sony FX3 Menu
FX3 Menu

Sony also updated the menu system in the effects on the FX3 and includes the ability to touch swipe to get the function menu up as well as two separate custom menus and be able to touch and get into different menu items and access them much quicker.

Sony A7S III Menu
A7S III Menu


So, FX3 has the same sensor as the A7S III but they’re calling it a 10.2 megapixel sensor because of the aspect of a 4K video frame, and when you shoot stills you would get 12 megapixels just like you would with the A7S III.

sony FX3 Sensor

So, both cameras feature the same 12.9 megapixels 35.6 by 23.8-millimeter full-frame sensor, the same rated 15 plus stops of dynamic range, both feature the same chipsets so the image produced should be identical between them.

Sony A7S III Sensor

As we see both cameras have pretty much the same features but after Sony’s release, the new version 2 firmware for the Sony FX3 and added a bunch of new features that the Sony A7S III doesn’t have makes the FX3 the better camera to shoot video.


FX3 has a focal plane shutter which you can shoot stills they put in a power zoom rocker so if you’re using one of their power zoom lenses you can zoom it right from there.


Sony FX3 ISO

FX3 ISO goes from 80 to 102400 natively which is insane and it expands all the way up to 400 plus thousand it has 627 phase detect autofocus points that cover 89 of the frame which is very similar to what you have in the A7S III.


In terms of the noise level, it actually looks almost exactly the same so whether you bump ISO on your camera or if you just leave it at 800 or 12 800 and just leave the images underexposed and then raise exposure and post later the noise levels are the same so if you’re on ISO 800 that’s the cleanest possible imagery.

For example, log shooting mode on FX3 allows you to shoot in three different T modes when recording an S log-3 cinee, slot 2 has also been removed from the camera, and you can ingest up to 16 user luts into the FX3, with the new vmcbnc m1 adapter cable you can use the USB micro on the camera to jam time code.

Recording Modes

Sony FX30 Recording Format

they both have the same recording resolutions codecs and frame rates internally and externally, the same inputs and outputs across their bodies, the same media options, and a similar core menu system.


When it comes to weight and size and look at these cameras side by side you can see that the fx3 is a wider and thicker the A7S III weighs 614 grams whereas the FX3 weighs 640 grams.

Sony FX3 vs A7S III Price

Sony FX3 vs A7S III Price

When it comes to the price the A7S III is cheaper than the FX3, the A7S III is going to run you $3,500 and the FX3 is going to cost you $3,900 which is only a $400 price difference which really isn’t too much between them, and with all that which camera should, you get the FX3 or the A7S III.

It really matters what category you look for is it a Sony line like Sony A1 or if you’re looking for a camera with a small size and weight like A7S III then you can go for a camera like the Sony A7C or the ZV-1.

So, those cameras can produce similar results to A7S III so consider that there’s no internal ND Filter on FX3 whereas the FX6 has ND, and the Sony ZV-1 also has an ND filter.

first of all, you have to think of the sony camera line in three different categories you have your consumer products cameras like the sony ZV-1 and the Sony RX100.

Why You Should Buy FX3 Over A7S III?

  • Number one is the EVF on it which is really strong sunlight definitely exposed and frames your shot and looks a lot better with an EVF.
  • Second A7S III has one of the greatest EVF because of that EVF, makes it definitely a better camera for photography than the FX3.
  • So the third reason to choose the A7S III is cheaper for $400 than FX3 with the FX3, you do get the XLR adapter, which is fantastic and slightly lighter in weight and because this just looks more like a traditional camera.
  • So, number four to switch from A7S III and get an FX3 is because of Cine EI and the Lut display built Sony ZV-1 into the FX3.
  • the FX3 it has a smaller unit than theA7S III and the fact that there’s no electronic viewfinder the direct angle behind that is very small almost more like an Sony A6400 or Sony A7C without the electronic viewfinder and once again if the viewfinder is not important to you having that extra space on the top of the camera is great it actually makes the rig even smaller than the A7S III.
  • FX3 is built-in xlrs for audio a built-in handle to be able to quickly carry it and get low shots with it FX3 has the integrated cooling fan and heat sink to be able to not worry about overheating.

Why You Should Buy A7S III Over FX3?

the Sony A7S III features a full frame sensor with roughly about 12.1 megapixels it is amazing in low light giving you an ISo of up to 400 and 9600. It records in 4k 120 and can give 4:2:2 10 bit, it has two SD cards slots and two CFexpress types A locks.

the A7S III has great photography options and the video options the capabilities in lowlight this camera is an absolute beast for freelancers.

So, if you do video FX3 maybe is not for you because I prefer shooting video with an EVF you can do rely on a flip out screen or an external monitor.

the viewfinder has more than 9 million dots the LCD screen is articulated and has 1.4 million dots it also has a full size HDMI.

What Are the Main Advantages of the FX3 over the A7S III?

  • So, first, the FX3 has a cooling fan on the back of the camera to cool down the camera if you’re shooting in 4k at a high bit rate and it can shoot uninterrupted 4k video at 60 fps.
  • Second, it has three record lamps one on the front one on the top, and one in the rear, three record tele lamps, and then a few more unique things about the fx3 that’s different from the A7S III the fx3 has a zoom rocker where you can zoom out.
  • And last, the FX3 can record four channels of 24-bit audio recording whereas the A7S III can record two channels. the only advantage that the A7S III has over the FX3 is that it has an EVF.

Where Sony FX3 Wins Over A7S III?

FX3 also has some additional features that really make it stand out such as having a built-in fan, six quarter mount screw holes which allow you to get really creative and mount the camera wherever you want. it has two record buttons it has three tally lights it has a zoom toggle switch a full size HDMI port, it has a handle with two xlr outputs.

the FX3 is a cinema version of the A7S III but the FX3 offers the big benefit of a motion-centric camera control with clean HDMI output which works at the same time as the rear LCD and a professional and removable xlr audio input which is included with the camera.

Wrapping Up

Why you would choose FX3 over the A7S III so whether the FX3 is better than another type of camera it seems like the FX3 makes more sense the difference between them and the good thing is they’re not that different but worth spending a little bit more money.


So the conclusion the FX3 and the A7S III are both very similar cameras with just a few differences the FX3 is designed for the filmmaker, and the A7S III is designed for hybrid shooters.

So, which one should you buy if you really want the EVF and if you want a more traditional shooting you can go with A7S III if you need a camera for the video you can go with FX3.

the FX3 is a small cinema line that can produce great performances it’s a camera for hybrid shooters that shoot photos and videos.

Sony FX3

Sony A7S III

Release Date23 February 202128 July 2020
Body Type SLR Style MirrorlessSLR Style Mirrorless
Sensor type Full Frame CMOSBSI CMOS
Sensor size 35.6 x 23.8 mm35.6 x 23.8 mm
Sensor resolution4240 x 28324240 x 2832
Sensor pixels1212
ProcessorBionz XRBionz XR
Expandable 40-409600
Expandable 40-409600
Image stabilization5 axis 5.5 stops5 axis 5.5 stops
Focus type HybridHybrid
Focus points759759
Manual FocusYesYes
Lens MountSony ESony E
Focal Length Multiplier1x1x
Screen TypeFully Articulated LCDFully Articulated LCD
Screen Size3.0″3.0″
Screen Resolution1,440,000 dots1,440,000 dots
Viewfinder typeOptical Not IncludedElectronic Oled
Viewfinder resolutionN/A9,440k dots
Viewfinder coverage100%
Shutter typeMechanical & ElectronicMechanical & Electronic
Shutter speedMin 30 sec
Max 1/8000 sec
Min 30 sec
Max 1/8000 sec
Video resolution4k 120fps
HD 240fps
4k 120fps
HD 240fps
Storage typeDual SD/CFexpress Type A slotDual SD/CFexpress Type A slot
Build in BluetoothYesYes
Build in Flash NONO
External flash YesYes
Battery life 580 shots600 shots
Continuous drive10fps10fps
Dimensions129.7 x 84.5 x 77.8 mm129 x 97 x 81  mm

Which Camera You Should Buy Sony FX3 or Sony A7S III?

the FX3 will be the cheaper option for example if you want to add audio as a source into A7S III and you’re using just your standard on-camera microphone and you’re plugging directly into the input so you would have to buy some sort of external recorder you’re almost to the same price as FX3 or you have to buy the xlr unit which retails for $600 so you’re $200 more than the FX3.


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